"The decision is a blow to the Enbridge project, which aims to replace two aging oil pipelines with a single tunnel under the Straits of Mackinac."

"Michigan’s highest court has ordered state energy regulators to redo their environmental review of Enbridge’s Line 5 tunnel project beneath the Straits of Mackinac.

The Michigan Supreme Court’s Friday ruling marks a major setback for the project, which saw a burst of momentum in July when Democratic Gov. Gretchen Whitmer’s administration issued key permits for construction.

Enbridge plans to replace a four-mile dual pipeline segment on the bottom of the straits with a single pipeline encased in a cement tunnel beneath the lake bed. The proposed 21-foot-diameter tunnel is meant to address long-standing concerns that the existing aging pipes are at risk of spilling oil into the Great Lakes."

Niina H. Farah and Carlos Anchondo report for E&E News August 3, 2026.  [2]

SEE ALSO:

"Michigan Supreme Court Vacates Key Line 5 Permit" (Bridge Michigan) [3]

"Attorneys And Advocates Cheer Michigan Supreme Court Decision Demanding New Line 5 Permit Review" (Michigan Advance) [4]